Setting Up an IPM Motor Model in Motor-CAD for Optimization
Hello everyone, welcome back. In the last video, we introduced the process of optimizing IPM motors using MotorCAD and OptiSlang. Now, let's dive into the first step: setting up our motor model in MotorCAD.
Creating a New Motor Design
We start by creating a new motor design by modifying one of the default templates. In this case, we'll use the E8 template, which is an IPM design based on the motor inside a 2012 Nissan Leaf. Let's modify the parameters to create a more unique design.
Switching to Ratio-Based Parameterization
I'm going to switch the motor template to ratio-based parameterization in MotorCAD. This approach simplifies scaling and optimization by using ratios rather than fixed dimensions. These ratios link key dimensions like the stator bore, slot depth, and slot width in a tree structure that shows their levels of dependency.
- Adjusting the stator bore automatically scales the slot depth and width.
- Variables in the tree can be made independent by unchecking the scale box, keeping them constant even when parent dimensions are updated.
- For instance, unchecking the scale for the slot opening keeps it fixed while the slot width scales.
The interface also displays the mathematical equation governing each ratio, which is useful for understanding how changes propagate through the design and for fine-tuning specific dimensions.
Scaling Up the Motor Geometry
Using this approach, let's scale up the motor geometry to make it bigger and more powerful by modifying the stator lamination diagram:
- The stator lamination diameter is adjusted from 298 mm to 250 mm.
- The slot number is increased from 48 to 72.
- The pole number is increased from 8 to 12.
- To maintain radial symmetry, one rotor duct layer is removed, and the number of ducts in the remaining layers is increased from 8 to 12.
In the axial tab, some axial dimensions are also increased. In the winding tab, the wire gauge and the diameter of the rotor duct are increased until the wire slot fill value is as close to 1 as possible.
Material and Simulation Adjustments
In the input data tab, I changed the stator and rotor materials to a higher grade steel and switched to a stronger magnet. After these changes, I ran an electromagnetic simulation to test the design. The larger machine's operating point requires a supply voltage higher than what's available from the DC bus. To address this, I could:
- Increase the DC bus voltage.
- Lower the speed.
- Adjust the winding configuration.
I elected to test the motor at 2000 RPM. At this speed, the model solves without exceeding operating parameters. Key outputs include:
- Maximum torque
- Average torque
- Input and output power levels
- System efficiency of about 97.5%
The back EMF and phase voltages appear balanced, and the current values are consistent with a stable operating point at 2000 RPM. Overall, these parameters form a good baseline reference for future design modifications.
Preparing for Optimization with OptiSlang
Now that the model is ready, we're set to link it with OptiSlang for optimization. In the next video, I'll show you how to perform that integration, allowing you to seamlessly transition from design to optimization. To do this, you'll need to:
- Connect MotorCAD to OptiSlang.
- Register the necessary input and output parameters.
- Prepare for a sensitivity analysis.
If you're following along and have any questions, leave a comment below. Don't forget to subscribe so you don't miss the next part of our IPM motor optimization series. Thanks for watching. I'll see you next time.
Hello everyone, welcome back. In the last video, we introduced the process of optimizing IPM motors using MotorCAD and OptiSlang. Now, let's dive into the first step, setting up our motor model in MotorCAD. First, let's start by creating a new motor design by modifying one of the default templates.
In this case, we'll use the E 8. This is an IPM design that's based off of the motor inside of a 2012 Nissan Leaf. Now let's modify the parameters to make this a more unique design. I'm going to start by switching the motor template to ratio-based parameterization in MotorCAD.
This approach makes scaling and optimization much easier because it uses ratios rather than fixed dimensions. These ratios will link key dimensions like the stator bore, slot depth, and slot width in a tree structure that shows their levels of dependency.
For example, if I adjust the stator bore, the slot depth and width automatically scale with it. Any of these variables in the tree can be made independent if you want. By unchecking the scale box for certain parameters, I can keep them constant even when their parent dimensions are updated.
For instance, if I uncheck the scale for the slot opening, it stays fixed while the slot width scales. The interface also shows the mathematical equation governing each ratio.
This is incredibly useful for understanding how changes propagate through the design and for fine-tuning specific dimensions. Using this, let's try to scale up the motor geometry to make it bigger and more powerful. I'm going to change the stator lamination diagram.
The stator lamination diagram is divided into three sections. The stator lamination diameter is 298 mm to 250 mm.
I also increased the slot number from 48 to 72 and increased the pole number from 8 to 12. To maintain radial symmetry, I took out one of the rotor duct layers and increased the number of ducts in the remaining layers from 8 to 12. In the axial tab, I increased some of these axial dimensions.
In the winding tab, I increased the wire gauge and the diameter of the rotor duct. The rotor duct also had a radius of 7.2 mm until I saw that the wire slot fill value was as close to 1 as I could get it.
In the input data tab, I changed the stator and rotor materials to a higher grade steel, and I changed to a stronger magnet. I left everything else the same and ran an electromagnetic simulation to test it out.
Unsurprisingly, the larger machine's operating point requires a supply voltage higher than what's available from the DC bus. To fix this, I could increase the DC bus, lower the speed, or adjust the winding configuration. I elected to test the motor out at 2000 RPM.
At this speed, the model solves without exceeding operating parameters. Key outputs like maximum torque, average torque, and input output power levels are shown, along with a system efficiency of about 97.5%. The back EMF and phase voltages appear balanced.
With the DC bus, the motor is able to run at a speed of about 50 km per hour, which is the same as the DC supply, and the current values are consistent with a stable operating point at 2000 RPM.
Overall, these parameters form a good baseline reference which I can use to measure the effects of future design modifications. Now that the model is ready, we're all set to link it with OptiSlang for optimization.
In the next video, I'll show you how to perform that integration, allowing you to seamlessly transition from design to optimization. I'll walk through how to do this in a few minutes.
To do this, you'll need to connect the MotorCAD to OptiSlang, register the necessary input and output parameters, and prepare for a sensitivity analysis. If you're following along and have any questions, leave a comment below.
Don't forget to subscribe so you don't miss the next part of our IPM motor optimization series. Thanks for watching. I'll see you next time.
